SAAB 9000. Manual - part 42
9•18 Braking system
20.21 Rear wheel ABS sensor (arrowed)
20 Extract the sensor cable from the clip, and
carefully guide the connector through the
grommet in the wheelarch.
21 Slacken and withdraw the sensor retaining
bolt (see illustration), then extract the sensor
from the hub assembly.
Rear wheel sensors - refitting
22 Push the sensor into the drilling in the hub
assembly, then refit and tighten the retaining
bolt.
23 Using a feeler blade inserted between the
sensor tip and the toothed disc, set the
clearance to the value listed in Specifications.
When the clearance is correct, tighten the set
screw.
24 Refit the remainder of the components by
reversing the removal sequence.
Rear wheel sensors (later type) -
retro-fitting to pre-1990 models
Note: Vehicles from 1990 model year onwards
are fitted with a different type of wheel sensor
and toothed disc. The sensors can be retro-
fitted to pre-1990 model year cars, as follows.
25 Slide the adjusting sleeve off the old
sensor, after slackening the set screw.
26 If renewing the fibre spacer on a used
sensor, ensure that all traces of the old spacer
are removed, using a fine wire brush and a rag
moistened with a suitable solvent. Once the tip
of the sensor is clean, peel the backing film
from the rear of the new 0.65 mm thick fibre
spacer, and press it onto the tip.
27 Slowly turn the brake disc by hand, and
using a fine wire brush, clean off any traces of
dirt and old fibre spacer from the toothed disc.
28 Insert the sensor into the drilling in the hub
assembly, and tighten the retaining bolt.
Gently push the spacer against the surface of
the toothed disc, and tighten the set screw.
Caution: Do not rotate the
toothed disc until the sensor has
been secured in position, or the
disc teeth may gouge the fibre
spacer, giving an incorrect sensor
clearance.
Electronic control unit (ECU)
Removal
29 Disconnect the battery negative cable,
and position it away from the terminal.
30 The ECU is mounted in the engine bay,
behind the false bulkhead panel. Remove the
left-hand cover to expose it.
31 Open the clips that secure the ECU in
position. Lift the ECU slightly to allow access
to the multi-plug connector, then unplug it by
releasing the clamp bar.
Caution: The ECU contains
components that are sensitive to
the levels of static electricity
generated by a person during
normal activity. Once the multi-plug
harness connector has been unplugged, the
exposed ECU pins can freely conduct stray
static electricity to these components,
damaging or even destroying them - the
damage will be invisible, and may not
manifest itself immediately. Expensive
repairs can be avoided by observing the
following basic handling rules:
a) Handle a disconnected ECU by its case
only; do not allow fingers or tools to come
into contact with the pins.
b) When carrying an ECU around, "ground"
yourself from time to time, by touching a
metal object such as an unpainted water
pipe, this will discharge any static that
may have built up.
c) Do not leave the ECU unplugged from its
connector for any longer than is absolutely
necessary.
Refitting
32 Refit the ECU by reversing the removal
procedure.
Warning: After working on any
part of the braking system, test
the vehicle exhaustively before
bringing it back into service. Make
sure that all warning lights go out, check all
disturbed joints and unions for leaks, and
top-up the fluid level in the reservoir to the
"MAX" mark. Finally, repeatedly check that
the braking system is capable of stopping
the vehicle normally, before taking it out
onto public roads.